This invention relates to a carrier system having one or more carriers movable along a path and which have one or more drive wheels engageable with a rotatable drive tube to impart speed and travel direction to the carrier.
Carrier systems having a carrier movable along a track and propelled by power derived from a rotatable drive tube extending along the track and which is engaged by one or more angularly adjustable drive wheels mounted on the carrier have been in existence for many years. The drive wheels have an angular adjusting movement between a position generally normal to the axis of rotation of the drive tube whereby rotation of the drive tube rotates the drive wheel without any linear motion imparted to the carrier and a limit position in which the drive wheel is related to the drive tube at a maximum angle and the drive tube imparts a component of force to the carrier through the drive wheel to propel the carrier along the guide track.
The carrier systems of this type have many different uses including transport of materials and various manufacturing operations. The carrier system may have a carrier movable back and forth along a track or have plural carriers movable unidirectionally along the track.
One control for the carriers in such carrier system can be the stopping of a carrier at a stop station. The stopping of the carrier at the stop station is achieved by means which cause the drive wheel to move from an angled position to a position approximately normal to the rotation axis of the drive tube. Subsequently, the drive wheel returns to an angled position for movement of the carrier from the stop station. Another control can be accumulation of carriers whereby, as one carrier approaches a preceding stationary carrier the approaching carrier will be caused to slow down and stop at a position immediately adjacent and to the rear of the preceding stationary carrier.